package main

import "fmt"


type Car interface{

    Say() int
}


type Bmw struct{
    Price   int
}

type Audi struct{

    Price   int
    Name    string
}

func (this Bmw)Say() int{
    fmt.Println("i am cost ", this.Price)
    return this.Price
}

func (this Audi)Say() int{
    fmt.Printf("i am cost %d, my name is %s\n", this.Price, this.Name)
    return this.Price
}

type ST struct{
  names []Car
}



func (s *ST) Set() {
    s.names = append(s.names, nil)
}


func main(){

    s := &ST{}
    s.Set()
    fmt.Println(s)
}
